5.8. Parsing a Session Description

5.8. Parsing a Session Description

The SDP contained in the session description object consists of a sequence of text lines, each containing a key-value expression, as described in [RFC4566], Section 5. The SDP is read, line by line, and converted to a data structure that contains the deserialized information. However, SDP allows many types of lines, not all of which are relevant to JSEP applications. For each line, the implementation will first ensure that it is syntactically correct according to its defining ABNF, check that it conforms to the semantics used in [RFC4566] and [RFC3264], and then either parse and store or discard the provided value, as described below.

If any line is not well formed or cannot be parsed as described, the parser MUST stop with an error and reject the session description, even if the value is to be discarded. This ensures that implementations do not accidentally misinterpret ambiguous SDP.